Metal rollers used in industry tend to wear out in certain areas, including their edges, and the roller surface are often roughened so that their surface must be periodically ground or refinished. According to the traditional method, a roller is removed from the rolling mill and it is generally ground or refinished one of three ways: i) using a conventional stone grinding wheel on a roll grinding machine; ii) by using a continuous, abrasive-tape finishing machine; or iii) by using an abrasive-belt finishing machine.
Using the first grinding technic discussed above, a stone grinding wheel is brought against the desired surface to be finished and the stone grinding wheel is caused to rotate against the surface. This possesses a number of significant disadvantages. For instance, due to the requirement that the stone grinding wheel must be soft enough to be self-dressing and to provide the desired material removal characteristics, the stone, through continued use, takes on the shape of the part being finished. Further, it is extremely difficult to find a stone grinding wheel with consistent qualities. This usually causes significant differences in the finished parts when machined by different stones. Another major disadvantage of the grinding machine using a stone grinding wheel is that the wheel has to be rebalanced and adjusted on the spindle of the grinding machine as the stone wheel wears.
As previously stated, the second finishing technic discussed above uses a machine having a continuous abrasive-tape. Using an continuous, abrasive-tape finishing machine, the surface being finished is caused to rotate (unlike the conventional grinding machine using a stone wheel where the grinding wheel is rotated). As the part is rotated, the tape is released from a tape cassette or spool and the tape is bought into contact with the surface to be finished by pressure exerted by compression rollers or platens.
Although this finishing equipment provides a more reliable and consistent finish because of the consistency with abrasive-belts, it to has its disadvantages. One of the disadvantage is the waste associated therewith. An abrasive-tape grinding machine is continuously fed from an abrasive-tape cassette such as that taught by Ohki, et al., U.S. Pat. No. 4,575,972, and by Johnson, U.S. Pat. No. 4,796,387. As a result, the abrasive-tape only comes in contact with the working surface once during the grinding process before it is discarded,. thereby causing waste and increase cost of the finishing process.
Finally, the third finishing technic uses an abrasive-belt (instead of abrasive-tape) which may overcome the waste problem, yet has other disadvantages. For example, these machines typically have a uniquely design, whereby it only uses a particular diameter abrasive-belt configured over multiple rollers which mechanically apply pressure against the belt as shown by the Nelson patent, U.S. Pat. No. 4,316,349. A major disadvantage with these machines is that they cannot be easily adapted for any other abrasive-belt configuration and the user is generally confined to depend upon the particular manufacturer of the equipment for replacement abrasive-belts and parts, making the equipment less desireable to the user. Further, these type machines are used typically for grinding non-circular work.
With the advent of improved coatings and adhesives for abrasive-belts, as well as improved grinding abrasive materials such as man-made crystals, refined sands and diamonds, many users owning roll grinding machines would prefer to convert their equipment to take advantage of the consistency of the abrasive-belt versus stone grinding wheel, instead of buying new finishing equipment which would accommodate abrasive-tapes or belts. Yet, such conventional stone grinding machines require a complicated and complex process for conversion, including substantially modifying the existing grinding machine to include a belt guard, guide rollers and compression member or platens typically required. Further, belt grinding attachment conversion kits require additional space which on many conventional stone grinding machines is not available.
Consequently, a need exists for a device to convert a conventional stone grinding machine to take advantage of the improved reliability, consistency and flexibility of abrasive-belts without requiring major modification to the grinding machine.